package mianshiti;

import java.util.HashSet;

public class Yu {
	public static void main(String[] args) {
		String str = null;
		// System.out.println(str instanceof String);
		// System.out.println("".equals(str));
		// System.out.println(str.equals(""));
		// short s = 1;
		// // s=(short) (s+1);
		// s += 1;
		// xuhuan();
		// Integer i = 0;
		// maopao();
		hash();
	}

	public static void xuhuan() {
		int a[][] = { { 1 }, { 2, 3 }, { 4, 5, 6 } };
		ok: for (int i = 0; i < a.length; i++) {
			for (int j = 0; j < a[i].length; j++) {
				System.out.println(i + "," + j);
				if (a[i][j] == 5)
					break ok;
			}
		}
	}

	public static void maopao() {
		int a[] = { 64, 35, 34, 55, -4 };
		for (int i = 0; i < a.length - 1; i++) {
			for (int j = 0; j < a.length - i - 1; j++) {
				if (a[j] > a[j + 1]) {
					int temp = a[j];
					a[j] = a[j + 1];
					a[j + 1] = temp;
				}

			}
		}
		for (int i = 0; i < a.length; i++) {
			System.out.println(a[i]);

		}
	}

	public static void hash() {
		HashSet set = new HashSet();
		set.add(new A());
		set.add(new A());
		for (Object hs : set) {
			System.out.println(hs);
		}
	}
}

class A {
	int a;

	public A() {
	}

	public static boolean equas(Object obj) {
		// TODO Auto-generated method stub
		return false;
	}

	@Override
	public int hashCode() {
		// TODO Auto-generated method stub
		return 1;
	}
}